Ack ignores node_modules by default
When searching through your JavaScript project it doesn't make sense to search through your node_modules. But if your are on a spelunking journey into the depths of your dependencies, you may want to search through all your node_modules!
ack ignores node_modules by default, and ack being ack you can ack through ack to check it out:
> cat `which ack` | ack node_modules
--ignore-directory=is:node_modules
This is different behaviour from ag and rg which also ignore node_modules but not explicitly. They both ignore node_modules by ignoring all entries in the .gitignore file.
rg claims to implement full support for the .gitignore file while also claiming other search tools do not. The open issues list for ag bears that out.
With each of these tools, explicitly stating the directory to search through overrides the ignore.
> ack autoprefix node_modules
> rg autoprefix node_modules
> ag autoprefix node_modules